Heart disease frequently leads to cardiac fibrosis. In almost all cases of chronic heart disease, the myocardium exhibits fibrosis developed by activated cardiac fibroblasts. These fibroblasts are quiescent in the healthy heart. Interstitial fibrosis due to extracellular matrix deposition by fibroblasts increases the stiffness of the tissue and impairs cardiac relaxation. Discovering pharmaceutical treatments that can reverse fibrosis is a critical unmet need;no such drugs currently exist. This project will develop a novel high-throughput screening platform for drug discovery that measures the physiological properties of live, engineered tissue samples, and their controls, cultured in 96-well plates(the PalpatorTM system). This platform will measure drug-induced changes in the physiological properties of engineered tissues. The Phase I project focuses on completing the development of the PalpatorTM screening system and obtaining feedback from academic and industrial collaborators. In addition, the algorithm used for the data analysis software will be modified to reduce failure rates. The modified software will be beta tested for its ability to obtain meaningful values for the physiological parameters used to indicate that treatment with the panel of chemical compounds has altered the properties of the engineered tissues. The final packaging of the project-related software will be outsourced for its launch. The Phase II project focuses on scaling up the engineered tissue-based screening system to make it amenable to high-throughput applications in industry. The tissue culture consumables for growing engineered tissues in 96-well plates will be produced in collaboration with Engineering Industries, Inc. (Verona, WI). The scaled-up engineered tissue production will significantly improve screening efficiency. This highly efficient Palpator screening system will be used to profile the effects of 50 commonly prescribed cardiovascular drugs on engineered heart tissues. Although the engineered heart tissues are constructed to mimic the physiological properties of native heart muscles, profiling known cardiovascular drugs will validate the utility of employing engineered heart tissues in drug discovery and toxic compound testing. To further validate the engineered tissue model, a library of compounds with known cardiovascular effects will be screened using the Palpator system. A novel phenotypic screening protocol that employs both engineered tissues cultured with highly contractile fibroblasts to mimic the fibrotic heart and 'normal'engineered heart tissues will be used to identify chemical compounds that reduce the contractility of the fibrotic engineered tissues but yet maintain the healthy contractile activities of normal engineered heart tissues. The combination of the engineered tissue models and the Palpator screening device will accelerate drug discovery and reduce the need (and associated costs) of extensive animal studies. PUBLIC HEALTH RELEVANCE: In the United States today, about 5 million people suffer from heart disease, one of the most prevalent chronic conditions and the number one complication of heart attacks. This proposal describes an entirely new method for testing potential drugs to learn if they can help repair the heart or if they are toxic to the body, by measuring whether a drug changes how a heart tissue model behaves. This research may provide a breakthrough in accelerating drug discovery and reducing costs, because it is rapid, high-throughput, and may reduce the need for animal testing.